LCDS with integrated touch panels

ABSTRACT

An LCD with an integrated touch panel that prevents sensor malfunction by eliminating coupling noises includes an insulating substrate, a plurality of gate lines formed on the insulating substrate so as to extend in a first direction, a plurality of data lines formed in a second direction so as to intersect the plurality of gate lines, a plurality of thin film transistors (TFTs), each formed at an area defined by the gate lines and the data lines, a plurality of sensor lines formed in the same directions as the gate lines and the data lines, and a plurality of dummy lines formed in the same directions as the sensor lines.

RELATED APPLICATIONS

This application claims priority of Korean Patent Application No.10-2006-0110515, filed Nov. 9, 2006, the entire disclosure of which isincorporated herein by reference.

BACKGROUND

This invention relates to liquid crystal displays (LCDs) with integratedtouch panels, and more particularly, to LCDs with integrated touchpanels that prevent sensor malfunction by eliminating coupling noises.

A wide variety of display devices capable of displaying images areknown, including cathode ray tubes (CRTs), liquid crystal displays(LCDs), plasma display panels (PDPs), and so on. In such displaydevices, a touch panel may used as an input means adapted to sense alocation on a display screen to which pressure is applied, and a user ofthe touch panel can thereby easily enter data by touching the displayscreen with a pen, a finger, or the like.

In order to address issues relating to the thickness or size of a touchpanel, new types of LCDs with integrated touch panels are currentlybeing developed. In these, efforts are being made to reduce thethickness of the touch panel, which is an advantageous feature inmanufacturing thin LCDs. In addition, since it is not necessary toassemble separate modules, these new LCDs are particularly effective inincreasing production yields.

In an LCD having an integrated touch panel, a common electrode formed ona common electrode panel comes into contact with a sensor electrodeformed on a thin film transistor (TFT) array panel in response toexternal pressure of a finger or the like, so that a predeterminedvoltage is applied to a sensor line and then provided to a sensor so asto output a signal having a specific level.

However, in this arrangement, a common voltage distortion can occur dueto coupling between a data line formed on the TFT array panel and thecommon electrode formed on the common electrode panel. Whenever a datavoltage is applied to a data line, the common voltage becomes severelydistorted. Accordingly, the distorted common voltage is provided to thesensor through the sensor line, and since the sensor determines thepolarities of two signals, that is, a reference signal having a specificlevel and a signal derived from the distorted common voltage, thepolarities may be erroneously determined. Consequently, even when noexternal pressure is being applied to the touch panel, it mayerroneously report the application of an external pressure. Moreover,when an external pressure is being applied to the touch panel, it isdifficult to determine a coordinates signal that is indicative of theactual position corresponding to that external pressure.

BRIEF SUMMARY

In accordance with the exemplary embodiment described herein, an LCDwith an integrated a touch panel is provided that prevents sensormalfunction by eliminating coupling noises.

In one exemplary embodiment, an LCD comprises an insulating substrate, aplurality of gate lines formed on the insulating substrate so as toextend in a first direction, a plurality of data lines formed in asecond direction so as to intersect the gate lines, a plurality of thinfilm transistors (TFTs), each formed at an area defined by the gatelines and the data lines, a plurality of sensor lines formed in the samedirections as the gate lines and data lines, and a plurality of dummylines formed in the same directions as the sensor lines.

In another exemplary embodiment, an LCD with an integrated a touch panelcomprises a thin film transistor (TFT) array panel, including aplurality of gate lines formed on an insulating substrate so as toextend in a first direction, a plurality of data lines formed in asecond direction so as to intersect the gate lines, a plurality of thinfilm transistors (TFTs), each formed at an area defined by the gatelines and the data lines, a plurality of sensor lines formed in the samedirections as the gate lines and data lines, a plurality of dummy linesformed in the same directions as the sensor lines, and a printed circuitboard, including a first interconnection line for applying apredetermined voltage to the dummy lines, a second interconnection linefor applying a gate-off voltage in the gate driver connected to theplurality of gate lines, and a capacitor coupled between the first andsecond interconnection lines for eliminating coupling noises.

A better understanding of the above and many other features andadvantages of the novel touch screen LCDs of the present invention maybe obtained from a consideration of the detailed description of someexemplary embodiments thereof below, particularly if such considerationis made in conjunction with the appended drawings, wherein likereference numerals are used to identify like elements illustrated in oneor more of the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial schematic diagram of a first exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention;

FIG. 2 is an enlarged schematic detail view of a portion of theexemplary LCD of FIG. 1 encircled by the phantom line ‘A’ therein;

FIG. 3A is a partial plan view of a thin film transistor (TFT) arraypanel of the exemplary LCD of FIG. 1, showing a single, exemplary pixelthereof;

FIG. 3B is a partial cross-sectional view of the TFT array panel of FIG.3A, as seen along the lines of the section IIIb-IIIb′ taken therein;

FIG. 3C is an enlarged partial cross-sectional view of the TFT arraypanel of FIG. 3A, as seen along the lines of the section IIIc-IIIc′ andIIIc′-IIIc″ taken therein;

FIG. 4 is a partial plan view of a common electrode panel of theexemplary LCD of FIG. 1, showing a single, exemplary pixel thereof;

FIG. 5A is a partial plan view of an exemplary LCD with an integratedtouch panel including the TFT array panel of FIG. 3A and the commonelectrode panel of FIG. 4, showing a single, exemplary pixel thereof;

FIG. 5B is a partial cross-sectional view of the TFT array panel of FIG.3A, as seen along the lines of the section Vb-Vb′ taken therein;

FIG. 6 is a partial schematic diagram a second exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention;

FIG. 7 is a partial schematic diagram of a third exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention;

FIG. 8 is a partial schematic diagram of a fourth exemplary embodimentof an LCD with an integrated touch panel in accordance with the presentinvention; and,

FIG. 9 is a partial schematic diagram of a fifth exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention.

DETAILED DESCRIPTION

FIG. 1 is a partial schematic diagram of a first exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention, FIG. 2 is an enlarged schematic detail view of a portion ofthe exemplary LCD of FIG. 1 encircled by the phantom line ‘A’ therein,FIG. 3A is a partial plan view of a thin film transistor (TFT) arraypanel of the exemplary LCD of FIG. 1, showing a single, exemplary pixelarea thereof, FIG. 3B is a partial cross-sectional view of the TFT arraypanel of FIG. 3A, as seen along the lines of the section IIIb-IIIb′taken therein, and FIG. 3C is an enlarged partial cross-sectional viewof the TFT array panel of FIG. 3A, as seen along the lines of thesection IIIc-IIIc′ and IIIc′-IIIc″ taken therein

Referring to FIG. 1, in the first exemplary LCD with an integrated touchpanel, a TFT array panel 100 thereof includes a touch panel outputting acoordinates signal corresponding to a touch position on the touch panelwhen an external pressure is applied to the panel.

Respective pluralities of first and second sensor lines SL1_1 throughSL1_4 and SL2_1 through SL2_5 are respectively formed in generallyorthogonal first and second directions on an insulating substrate of theTFT array panel 100, and respective pluralities of first and seconddummy lines AL1_1 through AL1_4 and AL2_1 through AL2_5 are also formedthereon in the same directions as the first and second sensor linesSL1_1 through SL1_4 and SL2_1 through SL2_5, respectively. A referencevoltage Vref is applied to the first and second dummy lines AL1_1through AL1_4 and AL2_1 through AL2_5.

The first and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5 are connected to the first and second sensor electrodes 28 a and63 a, respectively. When an external pressure is applied to the frontsurface of the display in the vicinity of associated pairs of the sensorelectrodes, a sensor spacer 92 formed on the common electrode panel 200is electrically connected to the first and second sensor electrodes 28 aand 63 a of the TFT array panel 100, so that a predetermined voltage istransmitted to the first and second sensor lines SL1_1 through SL1_4 andSL2_1 through SL2_5.

In addition, the TFT array panel 100 includes a plurality of firstcomparators AMP1_1 through AMP1_4 respectively connected to the firstsensor lines SL1_1 through SL1_4 and the first dummy lines AL1_1 throughAL1_4 and amplifying voltage differences between each of the firstsensor lines SL1_1 through SL1_4 and each of the first dummy lines AL1_1through AL1_4 and then outputting the amplified voltage differences, anda plurality of second comparators AMP2_1 through AMP2_5 respectivelyconnected to the second sensor lines SL2_1 through SL2_5 and the seconddummy lines AL2_1 through AL2_5 and amplifying voltage differencesbetween each of the second sensor lines SL2_1 through SL2_5 and each ofthe second dummy lines AL2_1 through AL2_5 and then outputting theamplified voltage differences.

The purpose in forming the first and second dummy lines AL1_1 throughAL1_4 and AL2_1 through AL2_5 in the same directions as the first andsecond sensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5,respectively, in the first exemplary embodiment is described below.

In a convention touch screen embodiment, a common voltage may bedistorted due to coupling between data lines (not illustrated) formed onthe TFT array panel 100 and a common electrode (not illustrated) formedon the common electrode panel 200. This common voltage distortionbecomes more severe whenever there is a change in the data voltageapplied to the data lines. As a result, the distorted common voltage istransmitted to the first and second sensor lines SL1_1 through SL1_4 andSL2_1 through SL2_5, and the first and second comparators AMP1_1 throughAMP1_4 and AMP2_1 through AMP2_5 may then erroneously determine thepolarities of two signals, that is, the reference signal having aspecific level and a signal derived from the distorted common voltage.Thus, even if no external pressure is being applied to the display, thetouch sensor mechanism may still indicate that an external pressure isbeing applied. Moreover, even if an external pressure is actually beingapplied, it is quite difficult to determine the actual coordinates ofthe touch position corresponding to the external pressure.

To solve this problem, the first and second dummy lines AL1_1 throughAL1_4 and AL2_1 through AL2_5 are formed in the same directions as thefirst and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5, respectively, thereby ensuring that the first and second dummylines AL1_1 through AL1_4 and AL2_1 through AL2_5 are similarly affectedby coupling with the first and second sensor lines SL1_1 through SL1_4and SL2_1 through SL2_5 when the first and second sensor lines SL1_1through SL1_4 and SL2_1 through SL2_5 are affected by coupling from thecommon electrode of the common electrode panel 200.

The first and second dummy lines AL1_1 through AL1_4 and AL2_1 throughAL2_5 and the first and second sensor lines SL1_1 through SL1_4 andSL2_1 through SL2_5 have substantially the same phases. Accordingly, thecommon voltage is applied to the first and second comparators AMP1_1through AMP1_4 and AMP2_1 through AMP2_5 through the first and secondsensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5, and thereference voltage, which has same phase as the common voltage, isapplied to the first and second dummy lines AL1_1 through AL1_4 andAL2_1 through AL2_5. Next, the first and second comparators AMP1_1through AMP1_4 and AMP2_1 through AMP2_5 compare the common voltage withthe reference voltage and output a predetermined sensing voltageindicative of the coordinates data corresponding to a touch position tooutput ports of the first and second comparators AMP1_1 through AMP1_4and AMP2_1 through AMP2_5, based on the comparison result. Thus, sincethe first and second comparators AMP1_1 through AMP1_4 and AMP2_1through AMP2_5 compare the common voltage and a reference voltage thathas the same phase as the common voltage, an erroneous determination ofpolarity caused by a determination of relative polarities is prevented.

FIG. 2 is an equivalent circuit diagram illustrating display signallines and pixels, including a touch panel, in which the display signallines include gate lines indicated by GL and data lines indicated by DL.

Referring to FIG. 2, each pixel PX includes a switching device Qconnected to a corresponding one of the gate lines GL and acorresponding one of the data lines DL, a liquid crystal capacitorconnected to the switching device Q, and a storage capacitor.

In addition, the pixel PX includes the first sensor line SL1_1 and thefirst dummy line AL1_1 formed in the same direction as the gate linesGL, the second sensor line SL2_4 and the second dummy line AL2_4 formedin the same direction as the data lines DL, the first and second sensorelectrodes 28 a and 63 a connected to respective ones of the first andsecond sensor lines SL1_1 and SL2_4, the first comparator AMP1_1connected to the first sensor line SL1_1 and the first dummy line AL1_1,and the second comparator AMP2_4 connected to the second sensor lineSL2_4 and the second dummy line AL2_4.

Referring to FIGS. 3A through 3C, a gate line 22 is formed on aninsulating substrate 10 in the horizontal direction in the figures, anda gate electrode 26 is formed on the gate line 22 in the form of aprotrusion. A gate line end portion 24 is formed at an end of the gateline 22 to receive a gate signal from other layers or from the outsideand transmit the received gate signal to the gate line 22. The width ofthe gate line end portion 24 is expanded for connection to an externalcircuit. The gate line 22, the gate electrode 26, and the gate line endportion 24 constitute a gate interconnection line (22, 26, 24).

In addition, a storage electrode 25 overlaps a pixel electrode 82(described in more detail below) to form a storage capacitor, whichimproves the charge retention capacity of the pixel. The shape andarrangement of the storage electrode 25 may vary widely from thoseillustrated.

The first sensor line 28 b is formed on the insulating substrate 10 inthe same direction as the gate line 22, and the first sensor electrode28 a having an extended width is formed on the insulating substrate 10in the same direction as the first sensor line 28 b. The first sensorelectrode 28 a comprises one terminal of a touch panel sensor and isconnected to the first sensor pad 84 through a contact hole 72. When anexternal pressure is applied to the panel in the vicinity of the sensorpad, the first sensor electrode 28 a is electrically connected to thecommon electrode on a sensor spacer 92 (see FIG. 4) described in moredetail below, to then provide position information corresponding to theposition at which the external pressure, e.g., a finger touch, isapplied. The first sensor electrode 28 a and the first sensor line 28 bconstitute a first sensor interconnection line. Furthermore, the firstdummy line 29 is formed in the same direction as the first sensorinterconnection lines 28 a and 28 b. In the embodiment illustrated, thefirst sensor interconnection lines 28 a and 28 b and the first dummyline 29 are formed in the same layer as the gate interconnection line(22, 24, 26).

The gate interconnection line (22, 24, 26), the storage electrode 25,the first sensor interconnection lines 28 a and 28 b and the first dummyline 29 are preferably made of an Al-containing metal, such as Al or Alalloy, a Ag-containing metal, such as Ag or Ag alloy, a Cu-containingmetal, such as Cu or Cu alloy, a Mo-containing metal, such as Mo or Moalloy, Cr, Ti, or Ta.

In other possible embodiments, the gate interconnection line (22, 24,26), the storage electrode 25, the first sensor interconnection lines 28a and 28 b and the first dummy line 29 may have a multi-layeredstructure that comprises two conductive films (not illustrated) havingdifferent but respectively advantageous physical characteristics. One ofthe two films is preferably made of a low resistivity metal, includingan Al alloy, an Ag alloy, and a Cu alloy, for reducing the signal delayor voltage drop in the gate interconnection line (22, 24, 26), thestorage electrode 25, the first sensor interconnection lines 28 a and 28b or the first dummy line 29. The other film is preferably made of amaterial, such as a Mo, Cr, Ta or Ti containing metal, that has goodphysical, chemical and electrical contact characteristics with othermaterials, such as indium tin oxide (ITO) or indium zinc oxide (IZO).Examples of combinations of the two films include a lower Cr film and anupper Al (alloy) film and a lower Al (alloy) film and an upper Mo(alloy) film. However, the gate interconnection line (22, 24, 26), thestorage electrode 25, the first sensor interconnection lines 28 a and 28b and the first dummy line 29 may also be made of a variety of othermetals or conductors, as well.

A gate insulating layer 30 made of, for example, silicon nitride (SiNx),is formed on the gate interconnection line (22, 24, 26), the storageelectrode 25, the first sensor interconnection lines 28 a and 28 b andthe first dummy line 29.

A semiconductor layer 40 made of hydrogenated amorphous silicon orpolycrystalline silicon is formed on the gate insulating layer 30. Thesemiconductor layer 40 may have various shapes, such as an island shapeor a stripe shape. In the particular exemplary embodiment illustrated,for example, the semiconductor layer 40 is stripe shaped. When thesemiconductor layer 40 is formed in a stripe shape, it may be formed bypatterning in the same manner as the data line 62.

Ohmic contact layers 55 and 56 made using a material, such as silicideor n+ hydrogenated amorphous silicon doped with n-type impurities athigh concentration, are formed on the semiconductor layer 40. The ohmiccontact layers 55 and 56 may also be formed in an island shape or stripeshape and positioned below the drain electrode 66 and the sourceelectrode 65. When the ohmic contact layers 55 and 56 are formed in astripe shape, they extend below the data line 62.

A data line 62 and a drain electrode 66 are formed on the ohmic contactlayers 55 and 56 and the gate insulating layer 30. The data line 62extends in the vertical direction in the figures and intersects the gateline 22, which extend in the horizontal direction. The source electrode65 extends over the semiconductor layer 40 as a branch of the data line62. A data line end portion 68 is formed at one end of the data line 62.The end portion receives data signals from another layer or from anexternal circuit and transmits the data signals to the data line 62. Thedata line end portion 68 has an expanded width so that it can beconnected with the external circuit. The drain electrode 66 is separatefrom the source electrode 65 and is located on the semiconductor layer40 so as to face the source electrode 65 at the opposite side of thegate electrode 26. The drain electrode 66 comprises a bar-type pattern,which is formed on the semiconductor layer 40, and a drain electrodeextension 67 that extends from the bar-type pattern and has a wide areathat contacts a contact hole 76.

The data line 62, the source electrode 65, the drain electrode 66, thedata line expansion 67, and the data line end portion 68 constitute adata interconnection line (62, 65, 66, 67, 68).

The second sensor line 63 b that is formed in the same direction as thedata line 62 and the second sensor electrode 63 a that is a protrusionof the second sensor line 63 b having an extended width are each formedon the gate insulating layer 30. Here, the second sensor electrode 63 afunctions as a terminal of a touch panel sensor and is connected to asecond sensor pad 85 through a contact hole 73. Upon application of anexternal pressure, the second sensor electrode 63 a is electricallyconnected to the common electrode on a sensor spacer (92 of FIG. 4)described below, and information corresponding to the location at whichthe external pressure is applied to the display is provided. The secondsensor electrode 63 a and the second sensor line 63 b constitute asecond sensor interconnection line (63 a, 63 b). With respect to thelocation of the application of the external pressure, the first sensorinterconnection lines 28 a and 28 b provide horizontal, or latitudinal,coordinates and the second sensor interconnection lines 63 a and 63 bprovide vertical, or longitudinal, coordinates. A second dummy line 64is disposed in the same direction as the second sensor line 63 b. Inthis particular embodiment, the second sensor interconnection lines 63 aand 63 b and the second dummy line 64 are formed in the same layer asthe data interconnection line (62, 65, 66, 67, 68).

The interconnection line (62, 65, 66, 67, 68), the second sensorinterconnection line (63 a, 63 b), and the second dummy line 64 mayinclude a single layer made of at least one selected from the groupconsisting of Al, Cr, Mo, Ta, and Ti, or alternatively, may comprise amultilayered structure. For example, the interconnection line (62, 65,66, 67, 68), the second sensor interconnection line (63 a, 63 b), andthe second dummy line 64 are preferably made of a refractory metal, suchas Cr, Mo, or Ti. Also, the interconnection line (62, 65, 66, 67, 68),the second sensor interconnection line (63 a, 63 b), and the seconddummy line 64 may have a multilayered structure that includes alow-resistivity lower film (not illustrated) and a good-contact upperfilm (not illustrated). Examples of such multi-layered structuresinclude a double-layered structure having a lower Cr film and an upperAl (alloy) film, a double-layered structure having a lower Mo (alloy)film and an upper Al (alloy) film, and a triple-layered structure havinga lower Mo film, an intermediate Al film, and an upper Mo film.

The source electrode 65 has at least a portion overlapping thesemiconductor layer 40, and the drain electrode 66 faces the sourceelectrode 65 about the gate electrode 26 and has at least a portionoverlapping the semiconductor layer 40. Here, the ohmic contact layers55 and 56 are interposed between the semiconductor layer 40 and thesource electrode 65 and between the semiconductor layer 40 and the drainelectrode 66 to reduce the contact resistance therebetween.

A passivation layer 70 functioning as an insulating layer is formed onthe data interconnection line (62, 65, 66, 67, 68), the second sensorinterconnection line (61, 63), the second dummy line 64, and an exposedportion of the semiconductor layer 40. In this particular embodiment,the passivation layer 70 is preferably made of an inorganic insulator,such as silicon nitride or silicon oxide, a photosensitive organicmaterial having a good flatness characteristic, or a low dielectricinsulating material, such as a-Si:C:O and a-Si:O:F formed by plasmaenhanced chemical vapor deposition (PECVD). When the passivation layer70 is made of an organic insulator, the passivation layer 70 may includea lower film of an inorganic insulator and an upper film of an organicinsulator such that it exhibits the excellent insulating characteristicsof the organic insulator while preventing the exposed portion of thesemiconductor layer 40 from being damaged by the organic insulator bypreventing the exposed portion of the semiconductor layer 40 between thesource electrode 65 and the drain electrode 66.

The passivation layer 70 has a plurality of contact holes 73, 76 and 78exposing the second sensor electrode 63 a, the drain electrode 66 andthe data line end portion 68, respectively. The passivation layer 70 andthe gate insulating layer 30 have contact holes 72 and 74 exposing thefirst sensor electrode 28 a and the gate line end portion 24.

A pixel electrode 82, which is electrically connected to the drainelectrode 66 via the contact hole 76, is formed on the passivation layer70. The pixel electrode 82, with a data voltage applied thereto, createsan electrical field together with a common electrode of an uppersubstrate (not illustrated), thereby determining the orientation of themolecules of a liquid crystal layer (not illustrated) disposed betweenthe pixel electrode 82 and the common electrode.

In addition, a gate line pad 86 and a data line pad 88 are formed on thepassivation layer 70 such that they are electrically connected to thegate line end portion 24 and the data line end portion 68 through thecontact holes 74 and 78, respectively. Further, a first sensor pad 84and a second sensor pad 85 are formed on the passivation layer 70 suchthat they are connected to the first sensor electrode 28 a and thesecond sensor electrode 63 a through the contact holes 72 and 73,respectively. The pixel electrode 82, the first sensor pad 84, thesecond sensor pad 85, the gate line pad 86 and the data line pad 88 areall made of a transparent conductive material, such as ITO (indium tinoxide) or IZO (indium zinc oxide), or a reflective conductive layer,such as aluminum. The gate line pad 86 and the data line pad 88optionally supplement and protect adhesion between the gate line endportion 24 and the data line end portion 68 and an external device.

An alignment layer (not illustrated) may be coated on the pixelelectrode 82, the first sensor pad 84, the second sensor pad 85, thegate line pad 86, the data line pad 88 and the passivation layer 70 topre-align the molecules of the liquid crystal layer (not illustrated).

A common electrode panel of the LCD according to the first embodiment ofthe present invention is described in detail below with reference toFIGS. 4 through 5B.

FIG. 4 is a partial plan view of a common electrode panel of theexemplary LCD of FIG. 1, showing a single, exemplary pixel thereof. FIG.5A is a partial plan view of an exemplary LCD with an integrated touchpanel including the TFT array panel of FIG. 3A and the common electrodepanel of FIG. 4, showing a single, exemplary pixel thereof, and FIG. 5Bis a partial cross-sectional view of the TFT array panel of FIG. 3A, asseen along the lines of the section Vb-Vb′ taken therein.

Referring to FIGS. 4 through 5B, a black matrix 94 for blocking lightleakage, and a plurality of red, green and blue color filters 98sequentially arranged on respective pixels are formed on an insulatingsubstrate 96 preferably made of a transparent insulating material, suchas glass. In the particular exemplary embodiment illustrated, a redcolor filter 98 is formed on the exemplary pixel.

A sensor spacer 92 is formed on the black matrix 94. In the embodimentillustrated, the sensor spacer 92 may be formed as the color filter 98.

A common electrode 90 is formed on the black matrix 94, the color filter98 and the sensor spacer 92. The common electrode 90 is preferably madeof a transparent conductive material such as, but not limited to, ITO(indium tin oxide) and IZO (indium zinc oxide).

In addition, a support spacer 93 is formed on the common electrode 90.The support spacer 93 maintains a specific gap between the TFT arraypanel 100 and the common electrode panel 200, thereby forming apredetermined cell gap. The support spacer 93 may be made of, e.g., aphotosensitive resin. The support spacer 93 and the sensor spacer 92 areboth preferably disposed so as to overlap the black matrix 94. However,in an alternative embodiment, the support spacer 93 and the sensorspacer 92 may not overlap the black matrix 94.

An alignment layer (not illustrated) may be coated on the commonelectrode 90 to align liquid crystal molecules.

In an initial state where there is no external pressure applied, thatis, in the absence of an electric field, the sensor spacer 92 isseparated from the TFT array panel 100. However, upon application of anexternal pressure, the common electrode 90 provided on the sensor spacer92 contacts the first sensor pad 84 and the second sensor pad 85,thereby electrically connecting the common electrode 90, the firstsensor pad 84, and the second sensor pad 85.

As illustrated in FIG. 5B, the above TFT array panel 100 and the commonelectrode panel 200 are aligned and combined with each other, andsubsequently, a liquid crystal layer 300 is formed, thereby completingthe basic configuration of an exemplary embodiment of a touch screendisplay device in accordance with the present invention. The TFT arraypanel 100 and the common electrode panel 200 are aligned such that thepixel electrode 82 and the color filter 98 are precisely aligned witheach other.

In addition to the basic configuration described above, the touch screendisplay device also includes various other elements, includingpolarizers, a backlight unit, and so on. The polarizers (notillustrated) are provided at opposite sides of the basic configurationof a touch screen display device such that one of their polarizationaxes is, e.g., parallel to the gate line 22, while the other of theirpolarization axes is perpendicular to the gate line 22.

FIG. 6 is a partial schematic diagram a second exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention. In FIG. 6, a plurality of first and second sensor lines SL1_1through SL1_4 and SL2_1 through SL2_5 are respectively formed in firstand second directions on an insulating substrate 10 of a TFT array panel100 of the second exemplary embodiment.

A first dummy line AL1 is formed along the periphery of the insulatingsubstrate 10, and second and third dummy lines AL2_1 through AL2_4, andAL3_1 through AL3_5 are formed in the first and second directions,respectively. In this embodiment, the first dummy line AL1 is connectedto the second and third dummy lines AL2_1 through AL2_4 and AL3_1through AL3_5. A reference voltage Vref is applied to the first, secondand third dummy lines AL1, AL2_1 through AL2_4, and AL3_1 through AL3_5.

The first and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5 are connected to the first and second sensor electrodes 28 a and63 a, respectively.

When an external pressure is applied to the surface of the display, asensor spacer 92 formed on the common electrode panel 200 and located inthe vicinity of the applied pressure is electrically connected to thefirst and second sensor electrodes 28 a and 63 a formed on the TFT arraypanel 100, so that a predetermined voltage is transmitted to the firstand second sensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5.

In addition, the TFT array panel 100 includes a plurality of firstcomparators AMP1_1 through AMP1_4 respectively connected to the firstsensor lines SL1_1 through SL1_4 and the second dummy lines AL2_1through AL2_4 and amplifying voltage differences between each of thefirst sensor lines SL1_1 through SL1_4 and each of the second dummylines AL2_1 through AL2_4 and then outputting the amplified voltagedifferences, and a plurality of second comparators AMP2_1 through AMP2_5respectively connected to the second sensor lines SL2_1 through SL2_5and the third dummy lines AL3_1 through AL3_5 and amplifying voltagedifferences between each of the second sensor lines SL2_1 through SL2_5and each of the third dummy lines AL3_1 through AL3_5 and thenoutputting the amplified voltage differences.

The purpose in forming the first dummy line AL1_1 along the periphery ofthe insulating substrate 10 and the second and third dummy lines AL2_1through AL2_4 and AL3_1 through AL3_5 connected thereto in the secondexemplary embodiment is as follows.

When the first and second sensor lines SL1_1 through SL1_4 and SL2_1through SL2_5 are affected by coupling with the common electrodeprovided on the common electrode panel 200, the first dummy line AL1_1is made to be similarly affected by coupling with the first and secondsensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5. Accordingly,the first dummy line AL1_1 and the first and second sensor lines SL1_1through SL1_4 and SL2_1 through SL2_5 have substantially the samephases. Therefore, according to the second exemplary embodiment, as inthe first exemplary embodiment described above, the first and secondcomparators AMP1_1 through AMP1_4 and AMP2_1 through AMP2_5 prevent anerroneous determination of polarity, which may be caused due to thedetermination of relative polarities through the first and second sensorlines SL1_1 through SL1_4 and SL2_1 through SL2_5, and the second andthird dummy lines AL2_1 through AL2_4 and AL3_1 through AL3_5.

FIG. 7 is a partial schematic diagram of a third exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention. In the embodiment of FIG. 7, a plurality of first and secondsensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5 are formed infirst and second directions on an insulating substrate 10 of a TFT arraypanel 100 of the LCD.

A first dummy line AL1 is formed along the periphery of the insulatingsubstrate 10, and second and third dummy lines AL2_1 through AL2_4 andAL3_1 through AL3_5 are formed in the first and second directions,respectively. In this embodiment, the first dummy line AL1 is connectedto the second and third dummy lines AL2_1 through AL2_4 and AL3_1through AL3_5. An initial voltage Vs is applied to the first, second,and third dummy lines AL1, AL2_1 through AL2_4, and AL3_1 through AL3_5,and the initial voltage Vs is lower than a common voltage.

The first and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5 are connected to the first and second sensor electrodes 28 a and63 a, respectively. When an external pressure is applied to the screenof the display, a sensor spacer 92 formed on the common electrode panel200 is electrically connected to the first and second sensor electrodes28 a and 63 a formed on the TFT array panel 100, so that a predeterminedvoltage is transmitted to the first and second sensor lines SL1_1through SL1_4 and SL2_1 through SL2_5.

The TFT array panel 100 includes a plurality of first comparators AMP1_1through AMP1_4 respectively connected to the first sensor lines SL1_1through SL1_4 and the second dummy lines AL2_1 through AL2_4 andamplifying voltage differences between each of the first sensor linesSL1_1 through SL1_4 and each of the second dummy lines AL2_1 throughAL2_4 and then outputting the amplified voltage differences, and aplurality of second comparators AMP2_1 through AMP2_5 respectivelyconnected to the second sensor lines SL2_1 through SL2_5 and the thirddummy lines AL3_1 through AL3_5 and amplifying voltage differencesbetween each of the second sensor lines SL2_1 through SL2_5 and each ofthe third dummy lines AL3_1 through AL3_5 and then outputting theamplified voltage differences.

In addition, the TFT array panel 100 includes a plurality of thirdcomparators AMP3_1 through AMP3_4 respectively connected to output portsOL1_1 through OL1_4 of the first comparators AMP1_1 through AMP1_4 andfourth dummy lines AL4_1 through AL4_4 and amplifying voltagedifferences between each of the output ports OL1_1 through OL1_4 andeach of the fourth dummy lines AL4_1 through AL4_4 and then outputtingthe amplified voltage differences, and a plurality of fourth comparatorsAMP4_1 through AMP4_5 respectively connected to output ports OL2_1through OL2_5 of the second comparators AMP2_1 through AMP2_5 and fifthdummy lines AL5_1 through AL5_5 and amplifying voltage differencesbetween each of the output ports OL2_1 through OL2_5 and each of thefifth dummy lines AL5_1 through AL5_5 and then outputting the amplifiedvoltage differences. Here, a reference voltage Vref is applied to thefourth and fifth dummy lines AL4_1 through AL4_4 and AL5_1 throughAL5_5.

According to the third exemplary embodiment, which is a modification ofthe second embodiment, an initial voltage, which has been applied to thefirst and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5, is applied to the first, second and third dummy lines AL1, AL2_1through AL2_4, and AL3_1 through AL3_5, and the third and fourthcomparators AMP3_1 through AMP3_4 and AMP4_1 through AMP4_5 areconnected to the output ports of the first and second comparators AMP1_1through AMP1_4 and AMP2_1 through AMP2_5, respectively. The purpose ofthe foregoing arrangement is as follows.

When the initial voltage Vs, which has been applied to the first andsecond sensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5, isapplied to the first, second and third dummy lines AL1, AL2_1 throughAL2_4, and AL3_1 through AL3_5, the voltage applied to the first andsecond sensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5 and thevoltage applied to the first, second and third dummy lines AL1, AL2_1through AL2_4, and AL3_1 through AL3_5, are equal.

In other words, when no external pressure is applied to the display, thesame voltage is applied to the first and second sensor lines SL1_1through SL1_4 and SL2_1 through SL2_5, as well as to the first, secondand third dummy lines AL1, AL2_1 through AL2_4, and AL3_1 through AL3_5,so that the output of the first and second comparators AMP1_1 throughAMP1_4, and AMP2_1 through AMP2_5 is ‘0’.

In addition, when an external pressure is applied to the display, apredetermined voltage is applied to the first and second sensor linesSL1_1 through SL1_4 and SL2_1 through SL2_5, so that the first andsecond comparators AMP1_1 through AMP1_4 and AMP2_1 through AMP2_5output a high level signal and then input the high level signal to thethird and fourth comparators AMP3_1 through AMP3_4 and AMP4_1 throughAMP4_5. The third and fourth comparators AMP3_1 through AMP3_4 andAMP4_1 through AMP4_5 then compare the outputted high level signal withthe reference voltage Vref and output a high level signal. Accordingly,it is possible to effectively eliminate coupling noises occurring in thefirst and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5 because the first and second sensor lines SL1_1 through SL1_4 andSL2_1 through SL2_5 are unaffected by coupling from the common electrodeof the common electrode panel 200.

FIG. 8 is a partial schematic diagram of a fourth exemplary embodimentof an LCD with an integrated touch panel in accordance with the presentinvention. In the exemplary LCD of FIG. 8, a plurality of first andsecond sensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5 areformed in first and second directions on an insulating substrate 10 of aTFT array panel 100 of the LCD.

A first dummy line AL1 is formed along the periphery of the insulatingsubstrate 10, and the plurality of second and third dummy lines AL2_1through AL2_4 and AL3_1 through AL3_5 are formed in the same directionsas the first and second sensor lines SL1_1 through SL1_4 and SL2_1through SL2_5, respectively. In this embodiment, the first dummy lineAL1 is connected to the second and third dummy lines AL2_1 through AL2_4and AL3_1 through AL3_5. An initial voltage Vs is applied to the first,second, and third dummy lines AL1, AL2_1 through AL2_4, and AL3_1through AL3_5, the initial voltage Vs being lower than a common voltage.

The first and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5 are connected to the first and second sensor electrodes 28 a and63 a, respectively. When an external pressure is applied to the display,a sensor spacer 92 formed on the common electrode panel 200 iselectrically connected to the first and second sensor electrodes 28 aand 63 a formed on the TFT array panel 100, so that a predeterminedvoltage is transmitted to the first and second sensor lines SL1_1through SL1_4 and SL2_1 through SL2_5.

The TFT array panel 100 includes a plurality of first comparators AMP1_1through AMP1_4 respectively connected to first sensor lines SL1_1through SL1_4 and second dummy lines AL2_1 through AL2_4 and amplifyingvoltage differences between each of the first sensor lines SL1_1 throughSL1_4 and each of the second dummy lines AL2_1 through AL2_4 and thenoutputting the amplified voltage differences, and a plurality of secondcomparators AMP2_1 through AMP2_5 respectively connected to secondsensor lines SL2_1 through SL2_5 and third dummy lines AL3_1 throughAL3_5 and amplifying voltage differences between each of the secondsensor lines SL2_1 through SL2_5 and each of the third dummy lines AL3_1through AL3_5 and then outputting the amplified voltage differences.

In addition, the TFT array panel 100 includes a plurality of thirdcomparators AMP3_1 through AMP3_4 respectively connected to output portsOL1_1 through OL1_4 of the first comparators AMP1_1 through AMP1_4 andfourth dummy lines AL4_1 through AL4_4 and amplifying voltagedifferences between each of the output ports OL1_1 through OL1_4 andeach of the fourth dummy lines AL4_1 through AL4_4 and then outputtingthe amplified voltage differences, and a plurality of fourth comparatorsAMP4_1 through AMP4_5 respectively connected to output ports OL2_1through OL2_5 of the second comparators AMP2_1 through AMP2_5 and fifthdummy lines AL5_1 through AL5_5 and amplifying voltage differencesbetween each of the output ports OL2_1 through OL2_5 and each of thefifth dummy lines AL5_1 through AL5_5 and then outputting the amplifiedvoltage differences. Here, a reference voltage Vref is applied to thefourth and fifth dummy lines AL4_1 through AL4_4 and AL5_1 throughAL4_5.

The fourth exemplary LCD is a modification of the third exemplaryembodiment of FIG. 7, and has substantially the same configuration asthe latter, except that the second and third dummy lines AL2_1 throughAL2_4 and AL3_1 through AL3_5 formed in the same directions as SL1_1through SL1_4 and SL2_1 through SL2_5, respectively, are formed tointersect the second and first sensor lines SL2_1 through SL2_5 andSL1_1 through SL1_4, respectively. Therefore, the fourth exemplaryembodiment operates similar to and achieves substantially the samebenefits as those of the third exemplary embodiment of the presentinvention described above.

FIG. 9 is a partial schematic diagram of a fifth exemplary embodiment ofan LCD with an integrated touch panel in accordance with the presentinvention. In the exemplary embodiment of FIG. 9, a plurality of firstand second sensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5 areformed in first and second directions on an insulating substrate 10 of aTFT array panel 100 of the LCD.

A plurality of first and second dummy lines AL1_1 through AL1_4 andAL2_1 through AL2_5 are formed in the first and second directions, and athird dummy line AL3 is connected to the first and second dummy linesAL1_1 through AL1_4 and AL2_1 through AL2_5, respectively. Here, areference voltage Vref is applied to the first, second, and third dummylines AL1_1 through AL1_4, AL2_1 through AL2_5, and AL3.

The first and second sensor lines SL1_1 through SL1_4 and SL2_1 throughSL2_5 are connected to the first and second sensor electrodes 28 a and63 a, respectively. When an external pressure is applied to the display,a sensor spacer 92 formed on the common electrode panel 200 iselectrically connected to the first and second sensor electrodes 28 aand 63 a formed on the TFT array panel 100, so that a predeterminedvoltage is transmitted to the first and second sensor lines SL1_1through SL1_4 and SL2_1 through SL2_5.

In addition, the TFT array panel 100 includes a plurality of firstcomparators AMP1_1 through AMP1_4 respectively connected to the firstsensor lines SL1_1 through SL1_4 and first dummy lines AL1_1 throughAL1_4 and amplifying voltage differences between each of the firstsensor lines SL1_1 through SL1_4 and each of the first dummy lines AL1_1through AL1_4 and then outputting the amplified voltage differences, anda plurality of second comparators AMP2_1 through AMP2_5 respectivelyconnected to the second sensor lines SL2_1 through SL2_5 and the seconddummy lines AL2_1 through AL2_5 and amplifying voltage differencesbetween each of the second sensor lines SL2_1 through SL2_5 and each ofthe second dummy lines AL2_1 through AL2_5 and then outputting theamplified voltage differences.

In the fifth exemplary embodiment of FIG. 9, the TFT array panel 100 isconnected to a printed circuit board 300 on which a plurality ofcomponents for driving TFTs are mounted. As shown in FIG. 9, the printedcircuit board 300 includes a first interconnection line 311 throughwhich a predetermined voltage is applied to the first, second and thirddummy lines AL1_1 through AL1_4, AL2_1 through AL2_5, and AL3, a secondinterconnection line 313 through which a gate-off voltage Voff isapplied to gate lines GL1 through GLn, a gate driver 320 receiving thegate-off voltage Voff from the second interconnection line 313 andsequentially applying the gate-off voltage Voff to the gate lines GL1through GLn, and a capacitor C1 coupled between the firstinterconnection line 311 and the second interconnection line 313 foreliminating coupling noises occurring therebetween. A reference voltageVref is applied to the first interconnection line 311.

The capacitor C1 is disposed between the first interconnection line 311and the second interconnection line 313 of the fifth exemplaryembodiment of the present invention for the following reasons.

The gate-off voltage Voff is applied to the gate lines GL1 through GLnconnected to the gate driver 320, excluding gate lines GL1 through GLnto which a gate-on voltage Von has been supplied. Here, a common voltagemay be distorted due to coupling between the data lines formed on theTFT array panel 100 and the common electrode formed on the commonelectrode panel 200. In this case, upon application of the gate-offvoltage Voff to the gate lines GL1 through GLn, the voltage is alsocoupled with the common electrode or the data lines.

To solve this problem, the capacitor C1 is disposed between the firstinterconnection line 311 and the second interconnection line 313 tolevel-shift the gate-off voltage Voff supplied to the level of thereference voltage Vref, thereby applying the reference voltage Vref tothe first, second and third dummy lines AL1_1 through AL1_4, AL2_1through AL2_5, and AL3. Accordingly, the first and second sensor linesSL1_1 through SL1_4 and SL2_1 through SL2_5 and the first and seconddummy lines AL1_1 through AL1_4 and AL2_1 through AL2_5 havesubstantially the same phases. Therefore, in the fifth exemplaryembodiment, the first and second comparators AMP1_1 through AMP1_4 andAMP2_1 through AMP2_5 are prevented from making an erroneous polaritydetermination, which may be caused due to determination of relativepolarities through the first and second sensor lines SL1_1 through SL1_4and SL2_1 through SL2_5 and the first and second dummy lines AL1_1through AL1_4 and AL2_1 through AL2_5.

While the fifth exemplary embodiment has been described and illustratedwith the reference voltage Vref being applied to the first, second andthird dummy lines AL1_1 through AL1_4, AL2_1 through AL2_5, and AL3, theinvention is not limited to the particular example illustrated anddescribed, and the initial voltage Vs, which is applied to the first andsecond sensor lines SL1_1 through SL1_4 and SL2_1 through SL2_5, mayalso be applied to the first, second and third dummy lines AL1_1 throughAL1_4, AL2_1 through AL2_5, and AL3. In this case, a comparator havingthe same configuration as in the fourth exemplary embodiment may beemployed, that is, a comparator including first through fourthcomparators may be employed.

In accordance with the exemplary embodiments described herein, displaytouch panel sensor malfunction is prevented by eliminating couplingnoises.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims. It istherefore desired that the present embodiments be considered in allrespects as illustrative and not restrictive, with reference being madeto the appended claims and their functional equivalents rather than theforegoing description to indicate the scope of the invention.

1. An LCD with an integrated touch panel, comprising: an insulatingsubstrate; a plurality of gate lines formed on the insulating substrateso as to extend in a first direction and a plurality of data linesformed in a second direction so as to intersect the gate lines; aplurality of thin film transistors (TFTs), each formed at an areadefined by the gate lines and the data lines; a plurality of sensorlines formed in the same directions as the gate lines and data lines;and, a plurality of dummy lines formed in the same directions as thesensor lines.
 2. The LCD of claim 1, wherein the plurality of sensorlines includes first and second sensor lines formed in the first andsecond directions and the plurality of dummy lines include first andsecond dummy lines formed in the same directions as the first and secondsensor lines, respectively.
 3. The LCD of claim 2, wherein a referencevoltage is applied to the dummy lines.
 4. The LCD of claim 2, furthercomprising: a first comparator connected to the first sensor line andthe first dummy line and amplifying a voltage difference between thefirst sensor line and the first dummy line and then outputting the anamplified voltage difference; and, a second comparator connected to thesecond sensor line and the second dummy line and amplifying a voltagedifference between the second sensor line and the second dummy line andthen outputting the amplified voltage difference.
 5. The LCD of claim 2,wherein the first sensor line and the second sensor line are connectedto first and second electrodes, respectively, and wherein a commonvoltage is applied to the first sensor line and the second sensor linethrough the first and second electrodes when an external pressure isapplied to the touch panel in the vicinity of the electrodes.
 6. The LCDof claim 2, wherein the first sensor line and the first dummy line areformed in the same layer as the gate lines.
 7. The LCD of claim 2,wherein the second sensor line and the second dummy line are formed inthe same layer as the data lines.
 8. The LCD of claim 1, wherein theplurality of sensor lines includes first and second sensor lines formedin the first and second directions, respectively, and the plurality ofdummy lines includes a first dummy line formed along the periphery ofthe insulating substrate and second and third dummy lines formed in thefirst and second directions, respectively, the first dummy line beingconnected to the second and third dummy lines.
 9. The LCD of claim 8,wherein a reference voltage is applied to the first through third dummylines.
 10. The LCD of claim 8, further comprising: a first comparatorconnected to the first sensor line and the second dummy line andamplifying a voltage difference between the first sensor line and thesecond dummy line and then outputting the amplified voltage difference;and, a second comparator connected to the second sensor line and thethird dummy line and amplifying a voltage difference between the secondsensor line and the third dummy line and then outputting an amplifiedvoltage difference.
 11. The LCD of claim 8, wherein an initial voltageapplied to the sensor lines is applied to the first through third dummylines.
 12. The LCD of claim 11, wherein the initial voltage is lowerthan a common voltage.
 13. The LCD of claim 10, further comprising: athird comparator connected to the output port of the first comparatorand a fourth dummy line and amplifying a voltage difference between theoutput port of the first comparator and the fourth dummy line and thenoutputting the amplified voltage difference; and, a fourth comparatorconnected to the output port of the second comparator and a fifth dummyline and amplifying a voltage difference between the output port of thesecond comparator and the fifth dummy line and then outputting theamplified voltage difference.
 14. The LCD of claim 13, wherein areference voltage is applied to the third and fourth dummy lines.
 15. AnLCD with an integrated a touch panel, comprising: a thin film transistor(TFT) array panel, including a plurality of gate lines formed on aninsulating substrate so as to extend in a first direction and aplurality of data lines formed in a second direction so as to intersectthe gate lines, a plurality of thin film transistors (TFTs), each formedat an area defined by the gate lines and the data lines, a plurality ofsensor lines formed in the same directions as the gate lines and thedata lines, and a plurality of dummy lines formed in the same directionsas the sensor lines; and, a printed circuit board, including a firstinterconnection line for applying a predetermined voltage to the dummylines, a second interconnection line for applying a gate-off voltage inthe gate driver connected to the plurality of gate lines, and acapacitor coupled between the first and second interconnection lines foreliminating coupling noises.
 16. The LCD of claim 15, wherein theplurality of sensor lines includes first and second sensor lines formedin first and second directions, respectively, and the plurality of dummylines includes first and second dummy lines formed in the first andsecond directions, respectively, and a third dummy line connected to thefirst and second dummy lines, respectively.
 17. The LCD of claim 16,further comprising: a first comparator connected to the first sensorline and the first dummy line and amplifying a voltage differencebetween the first sensor line and the first dummy line and thenoutputting the amplified voltage difference; and, a second comparatorconnected to the second sensor line and the second dummy line andamplifying a voltage difference between the second sensor line and thesecond dummy line and then outputting an amplified voltage difference.18. The LCD of claim 16, wherein the first sensor line and the secondsensor line are connected to first and second electrodes, respectively,and wherein a common voltage is applied to the first sensor line and thesecond sensor line through the first and second electrodes when anexternal pressure is applied to the touch panel in the vicinity of theelectrodes.
 19. The LCD of claim 16, wherein the first sensor line andthe first dummy line are formed in the same layer as the gate lines. 20.The LCD of claim 16, wherein the second sensor line and the second dummyline are formed in the same layer as the data lines.
 21. The LCD ofclaim 15, wherein the predetermined voltage is a reference voltage or aninitial voltage applied to the sensor lines.